There's also the old 10/10 regen rate
CB sleep method.
This consists of taking 4x30 minute naps or 6x20 minute naps per day and no other sleep.
Apparently it works and while I haven't tried it I can attest to some of the effects described from when I had two full time jobs and was also going out partying every day during school holidays and surviving on naps in between and a 2 hour sleep.
